Inductor coil and bobbin with terminals



May 20, 1969 W. C. OTTO INDUCTOR COIL AND BOBBIN WITH TERMINALS Filed March 16, 1967 OQO OO 0 n ggg? INVENTOR WILL/AM C. OTTO BY ATTOR EY United States Patent O U.S. 'CL 336-192 15 Claims ABSTRACT OF THE DISCLOSURE A coil bobbin providing an electrical coil wherein the wire attaching terminals and the electrical terminals are unitarily constructed and wherein the wire terminates entirely within the coil.

The use of plastic material such as nylon for molding various shapes of bobbins for supporting electrical coils of a various nature is quite common in the manufacture of electromechanical products such as relays, transformers, reed switch activating coils, buzzers or the like. In such applications the bobbins are Igenerally molded to accommodate inserted metal tabs for securing the start and nish of the coil windings. This method has several disadvantages. For one, the terminals being inserted after molding rely upon some sort of barb which drops into the plastic in such a way that the terminal cannot be pulled out after it is once forced into place. Terminals of this type are usually capable of some ilexing in relation to the plastic bobbin itself. When an extremely small wire such as a #40 is attached to such terminals, it can be broken if a pull is exerted sidewise on the terminals.

As another example of the disadvantages encountered, the anchoring of the start lead from the inside of the coil to a normal inserted terminal requires that it be brought up in a slot provided or along the inside edge of the bobbin to the terminal. In either case, the small portion of the start lead, extending alongside of the coil and winding around the terminal itself, is exposed to mechanical abuse or corrosion for a short critical length.

The same situation applies to the finish of the winding in a normal bobbin where the wire is lead over and wrapped around the terminal and soldered. Although this construction does not present serious difficulty where relatively large wires, such as #28 or greater, are used, it provides a real drawback to a high quality construction of a coil which must stand serious environmental abuse as is the case in dishwashers, automatic washers, and so forth, where the wire size is considerably less than #28.

The present invention is concerned with a coil bobbin having a novel terminal arrangement and has as one of its objects the provision of a coil bobbin wherein the bobbin itself is molded with the wire-attaching terminals in place.

Another object of the invention is the provision of a bobbin wherein the attaching terminals and the electrical terminals are of a unitary construction.

Another object of the invention is the provision of a coil bobbin wherein the terminal for the end of the winding is at one edge of the bobbin near the outside diameter.

Still another object of the invention is the provision of a coil bobbin wherein the starting attaching terminal is at the point where in the winding actually starts.

Another object of the invention is the provision of a coil bobbin wherein thin metal tabs are provided at the starting and ending points so that the connections can be readily made to solderable winding wire.

Still another object of the invention is the provision of a coil bobbin wherein such connections are made to metal tabs or inserts that have been molded in place.

Yet another object of the invention is the provision of a coil bobbin wherein the external tip of the molded inserts are fashioned for conventional terminal designs.

Another object of the invention is the provision of a coil bobbin wherein there is no possible motion of the terminal in relation to the wire.

Still another object of the invention is the provision of a coil bobbin wherein both the start and the finish of the winding are within the winding itself.

Yet another object of the invention is to provide a bobbin with molded in place wire attaching terminals, integral with the external terminals such that when the winding for the bobbin is completed, the bobbin need not be separately handled for further production operations. With the above and other objects in view, which will appear as the description proceeds, this invention resides in a novel coil bobbin substantially as described herein and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the invention here disclosed may be made as come within the scope of the claims.

For illustrative purposes the invention will be described with reference to the accompanying drawings in which:

FIGURE l is a perspective View of the novel bobbin prior to the application of the winding.

FIGURE 2 is a vertical cross-section of the novel bobbin with the winding applied.

FIGURE 3 is a cross-section taken along line 3-3 of FIGURE 2.

FIGURE 4 is a perspective View of the preformed terminal assembly used in the bobbin.

Generally speaking, the objects of the invention are accomplished by providing a novel coil bobbin which in general comprises a spindle, a wire winding surrounding the spindle, the spindle carrying in substantially parallel spaced relation a rim and a terminal retaining rim, unitarily constructed terminals and wire attaching terminals carried by the terminal retaining rim, the wire attaching terminals being positioned such that one of the terminals is contiguous with the spindle, the other being in spaced parallel relation with the spindle at a distance substantially equal to the thickness of the winding applied to the spindle.

Referring now to the drawing, the novel coil bobbin is generally indicated by the reference numeral 10. The bobbin is molded `as a single unit having a spindle 11, a rim 12 and a terminal retaining rim 13. The spindle and the rim are, as indicated in the drawing, made from an electrically insulating plastic material. Electrical quick connect terminals 14 and 16 are also integrally molded into the terminal retaining rim 13. Thin Wire attaching terminals 15 and 17 are unitarily constructed with quick connect terminals 14 and 16 respectively prior to being molded into the retaining rim 13. Terminal 17 serves as the attachment for the start of the wire to be wound on the spindle, while terminal 15 serves as the attachment for the wire termination. As more clearly shown in FIG- URE 4, both terminals Ialong with their respective wire attaching terminals are fabricated as a single unit by fabricating them onto a carrier strip 22. This provides for ease of molding the terminals into the rim 13 of the bobbin and also insures that the terminals will be in alignment during the molding of the bobbin. After the bobbin has been molded carrier strip 22 is clipped olf.

It is noted with particular reference to FIGURES 1 and 2 that wire attaching terminal 15 is in the plane of the spade terminals 14 and 16 prior to its bent over so that the terminal does not interfere with the winding process. Further, thel terminal 17 is bent at right angles to the terminal retaining rim 13 so that it will lie along and 'be contiguous with the winding surface 11a of the spindle 11 where the start of the winding begins. Also,

in order to insure a smooth start to the winding, a notch 11b is formed in the surface 11a to receive the terminal 17 so that the terminal lies substantially ush with the surface 11a of the spindle.

The wire 18 to be wound is iirst attached to the wire attaching terminal 17 through some suitable means such as a tin/lead solder 21, for example. The wire is then wound around the spindle 11 to form a winding 18a. When the desired thickness of the winding 18a is reached, at least one layer of electrical insulating material 19, such as paper tape, is applied to the winding to form an electrical insulation wrapping around the winding. Terminal is then bent over and the end of the wire 18 is attached to the terminal through some suitable means such as solder 20, for example. At least one more layer of the electrical insulating material 19 is then applied to complete the coil bobbin.

By using the present novel bobbn an electrical coil can be provided which can be made of extremely fine wire terminating entirely within the coil with external connections which are rigid and which will withstand extremely great pull without transmitting strain on the wire connections. The present bobbin also permits the coil to be linished very economically because there is eliminated the tedious and time-consuming attachment of external leads and the miscellaneous bits and pieces involved in making connections, attaching leads, and securely anchoring in the finishing process of the coil.

Thus, for example, the concept of the invention can be used in a bililar bobbn wherein there are terminals at both ends of the bobbn spindle such that a double winding can be employed. In such case the attaching terminals and the electrical terminals would be molded in the rim 12, the same as in rim 13.

The coil bobbn of the present invention, as hereinbefore described in one of its embodiments, is merely illustrative and not exhaustive in scope. Since many widely dierent embodiments may be made without departing from the scope thereof, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interposed as illustrative and not in a limiting sense.

What is claimed is:

1. A bobbn for carrying a wire winding which comprises a spindle carrying in spaced substantially parallel relation a rim and a terminal retaining rim, unitarily constructed electric terminals and wire attaching Yterminals carried by said terminal retaining rim, said wire attaching terminal for the start of the winding being held in a notch cut in the wire winding face of said spindle, and the wire attaching terminal for the wire termination being held in a plane with said electrical terminals so as to not interfere with the wire winding process.

2. A coil bobbn comprising a spindle, a wire winding surrounding the spindle, said spindle carrying in substantially parallel spaced relation a rim and a terminal retaining rim, unitarily constructed electrical terminals and wire attaching terminals carried by said terminal retaining rim, said terminals being molded as a single unit with said terminal retaining rim, with said wire attaching terminals being disposed such that one of said terminals is contiguous with said spindle, the other of said terminals being in spaced parallel relation with the spindle at a distance from the spindle substantially equal to the thickness of the winding applied to the spindle.

3. A coil bobbn comprising a spindle, a wire winding surrounding the spindle, said spindle carrying in spaced parallel relation a rim and a terminal retaining rim, unitarily constructed electrical terminals and wire 4attaching terminals carried by said terminal retaining rim, said terminals being molded as a single unit with said terminal retaining rim, with said wire attaching terminals being disposed such that one of said terminals is contiguous with said spindle, the other of said terminals being in spaced parallel relation with the spindle at a distance from the spindle substantially equal to the thickness of the winding applied to the spindle, at least one layer of electrical insulation wrapping surrounding said Winding and having a portion thereof disposed between siad parallel spacedv attaching terminal and said winding, and at least one additional layer of said electrical insulation wrapping surrounding said first layer of wrapping and said spaced terminal.

4. A bobbin for carrying wound wire comprising a spindle, a rim and a terminal retaining rim carried by said spindle in spaced relationship, a plurality of unitary electrical terminal means and wire attaching terminal means carried by said terminal retaining rim, one of said wire attaching terminal means contiguous with the face of said spindle for providing termination for one end ofthe wound wire, and another of said wire attaching terminal means providing termination for another end of the wound wire.

5. A bobbn according to claim 4 wherein said rims are integral with said spindle.

6. A 'bobbn according to claim 4 wherein said wire attaching terminal means which is contiguous with said spindle is held in a notch provided in the face of said spindle.

7. A bobbn according to claim 4 wherein said terminal retaining rim is substantailly U-shaped.

8. A bobbn according to claim 4 wherein said spindle and said rims are made of an electrically insulative plastic.

9. A bobbn according to claim 4 wherein said electrical terminal means project from said terminal retaining rim at an angle substantially perpendicular to the axis of said spindle.

10. A bobbin according to claim 4 wherein said other wire attaching terminal means is bent means which terminates one end of said wound wire.

11. A bobbn according to claim 7 wherein said electrical terminal means are embedded in said substantially U-shaped member.

12. A coil bobbn comprising a spindle, a wound wire surrounding said spindle, a rim and a terminal retaining rim carried by said spindle in spaced relationship, a plurality of unitary electrical terminal means and wire attaching terminal means carried by said terminal retaining rim, said wire attaching terminal means disposed such that one of said terminal means is contiguous with said spindle, and another of said terminal means being in spaced, substantially parallel relation with said spindle at a distance from said spindle substantially equal to the thickness of said wound wire.

13. A coil bobbn according to claim 12 wherein there is at least one layer of electrical insulation surrounding said wound wire and having a portion thereof disposed between said parallel spaced attaching terminal and said Wound wire, and at least one additional layer of said electrical insulation surrounding said first layer and said spaced terminal.

14. In a method of making a coil bobbn as claimed in claim 12 comprising the steps of:

(a) providing a bobin having a spindle, a rim and a terminal retaining rim carried by said spindle in spaced relationship and a plurality of unitary electrical terminal means and wire attaching terminal means carried by said terminal retaining rim,

(b) attaching one end of a wire to said wire attaching means contiguous with the face of said spindle,

(c) winding said wire around said spindle and between said rims,

(d) attaching the other end of said wire to the other of said wire attaching means.

15. A bifilar coil bobbn comprising a spindle, a wound wire surrounding said spindle, a pair of terminal rims carried by said spindle in spaced relationship, a plurality of unitary electrical terminal means and wire attaching terminal means carried by said terminal retaining rims, said wire attaching terminal means being disposed such 5 6 that one of said terminal means is contiguous with said 3,014,164 12/ 1961 Howenstine 336-192 spindle, the other of said terminal means being in spaced, 3,230,489 1/ 1966 Weyrich 336-192 substantially parallel relation with said spindle and at 3,359,520 12/ 1967 Foerster 336-192 a distance from the spindle substantially equal to the thickness of said wound wire applied to said spindle. 5 LEWIS H. MYERS, Primary Examiner.

References Cited E. A. GOLDBERG, Assistant Examiner.

UNITED STATES PATENTS U.S. C1. X.R.

1,704,151 3/1929 simpson 336-192 29 6o5;336 198,208 2,956,312 10/1960 Naimer 336-198 10 

